Divide both sides by 0.8 to get x=.5 or x=1/2
The graph for this is a vertical line.
** I'm not sure about that particular Casio. Most graphing calculators cannot graph this, as it is not a function. It is linear, but there is no slope (the slope does not exist). You probably have a screen to input y="stuff", but this cannot be written in this form.
In fact, the grapher on this page only graphs functions, so I cheated to get a graph. You will notice that the line is not perfectly vertical.
Some calculators with a computer algebra system (CAS) can graph relations. My calculator will allow me to draw a vertical line, but I have to know where; it cannot take x=1/2 as input.